Conformal theory of central surface density for galactic dark halos

R. K. Nesbet

doi:10.59400/jam.v2i1.465

Conformal theory of central surface density for galactic dark halos

R. K. Nesbet IBM Almaden Research Center, 650 Harry Road, San Jose, CA 95120-6099, USA

Article ID: 465

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DOI: https://doi.org/10.59400/jam.v2i1.465

Keywords: galactic dark halos; conformal theory; dark matter

Abstract

Numerous dark matter studies of galactic halo gravitation depend on models with a core radius of r₀ and a central density of ρ₀. The central surface density product ρ₀r₀ is found to be nearly a universal constant for a large range of galaxies. Standard variational field theory with Weyl conformal symmetry postulated for gravitation and the Higgs scalar field, without dark matter, implies nonclassical centripetal acceleration $Δ a$ , for $a = a_{N} + Δ a$ , where Newtonian acceleration a_N is due to observable baryonic matter. Neglecting a halo cutoff at a very large galactic radius, conformal $Δ a$ is constant over the entire halo, and $a = a_{N} + Δ a$ is a universal function, consistent with a recent study of galaxies with independently measured mass, that constrains acceleration due to dark matter or to an alternative theory. An equivalent dark matter source would be a pure cusp distribution with a cutoff parameter determined by a halo boundary radius. This is shown to imply a universal central surface density for any dark matter core model.

References

[1]Kormendy J, Freeman KC. Scaling laws for dark matter haloes in late-type and dwarf spheroidal galaxies. Symposium - International Astronomical Union. 2004, 220: 377-397. doi: 10.1017/S0074180900183706

[2]Gentile G, Famaey B, Zhao H, et al. Universality of galactic surface densities within one dark halo scale-length. Nature. 2009, 461: 627.

[3]Donato F, Gentile G, Salucci P, et al. A constant dark matter halo surface density in galaxies. MNRA. 2018, 397: 1169.

[4]Mannheim PD. Alternatives to dark matter and dark energy. Prog. Part. Nucl. Phys. 2006, 56: 340.

[5]Mannheim PD, Kazanas D. Exact vacuum solution to conformal Weyl gravity and galactic rotation curves. ApJ. 1989, 342: 635.

[6]Mannheim PD, Kazanas D. Newtonian limit of conformal gravity and the lack of necessity of the second order Poisson equation. Gen. Rel. Grav. 1994, 26: 337.

[7]Mannheim PD. Some exact solutions to conformal Weyl gravity. Annals N.Y. Acad. Sci. 1991, 631: 194.

[8]Mannheim PD. Making the case for conformal gravity. Found. Phys. 2012, 42: 388.

[9]Nesbet RK. Cosmological implications of conformal field theory. Mod. Phys. Lett. A. 2011, 26: 893.

[10]Nesbet RK. Conformal gravity: dark matter and dark energy. Entropy. 2013, 15: 162.

[11]Nesbet RK. Dark energy density predicted and explained. Europhys. Lett. 2019, 125: 19001.

[12]Nesbet RK. Dark galactic halos without dark matter. Europhys. Lett. 2015, 109: 59001.

[13]Nesbet RK. Conformal theory of gravitation and cosmology. Europhys. Lett. 2020, 131: 10002.

[14]Nesbet RK. Conformal theory of gravitation and cosmic expansion. MDPI Symmetry. 2024, 16: 003.

[15]McGaugh SS, Lelli F, Schombert JM. The radial acceleration relation in rotationally supported galaxies. Phys. Rev. Lett. 2016, 117: 201101.

[16]Nesbet RK. Theoretical implications of the galactic radial acceleration relation of McGaugh, Lelli, and Schomber. MNRAS. 2018, 476: L69.

[17]Mohr PJ, Taylor BN, Newell DB. CODATA recommended values of the fundamental physical constants: 2010. Rev. Mod. Phys. 2012, 84: 1527.

[18]De Blok WJG. The core-cusp problem. Advances in Astronomy. 2010, 2010. doi: 10.1155/2010/789293

[19]Ou X, Eilers AC, Necib L, Frebel A. The dark matter profile of the Milky Way inferred from its circular velocity curve. MNRAS. 2024, 528: 693.

[20]Milgrom M. A modification of the Newtonian dynamics: Implications for galaxies. ApJ. 1983, 270: 371.

[21]Milgrom M. The central surface density of ‘dark halos’ predicted by MOND. MNRAS. 2009, 398: 1023.

[22]McGaugh SS. Milky Way mass models and MOND. ApJ. 2008, 683: 137.

[23]O’Brien JG and Moss RJ. Rotation curve for the Milky Way galaxy in conformal gravity. J. Phys. Conf. 2015, 615: 012002.

Published

2024-02-28

How to Cite

Nesbet, R. K. (2024). Conformal theory of central surface density for galactic dark halos. Journal of AppliedMath, 2(1), 465. https://doi.org/10.59400/jam.v2i1.465

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